Fatty acid oxidation complex subunit alpha; Involved in the aerobic and anaerobic degradation of long-chain fatty acids via beta-oxidation cycle. Catalyzes the formation of 3-oxoacyl-CoA from enoyl-CoA via L-3-hydroxyacyl-CoA. It can also use D-3-hydroxyacyl-CoA and cis-3-enoyl-CoA as substrate; In the N-terminal section; belongs to the enoyl-CoA hydratase/isomerase family (717 aa)